Support Effective Alternatives to Adulticide Spraying

Pesticide Facts

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    Our opposition to spraying pesticides from the air over populated areas to kill adult mosquitoes (adulticiding) rests on two very simple facts: 1) it does not work, and 2) it is dangerous to some people in the short term and adds to the overall pesticide load in the environment for the long term. The second point is moot given that adulticiding is ineffective, but it is important because spraying continues as West Nile virus recedes into a state known as chronic endemicity, one in which very few people are infected. Moreover, indiscriminate spraying can increase resistance in non-target insects so that there might be no effective control available when an actual threat appears, and it harms beneficial insects, whose recovery cycle is often much longer.  The question is not whether to spray; rather, it is if we should use effective means of control instead of ineffective and damaging ones. 

    Public officials have exaggerated the threat of WNv in an attempt to justify their spray protocol. Their statements and reasoning have shifted regularly since WNv became a concern in this region in 2005, always suggesting that we must use indiscriminate aerial spraying. However, a sensible public policy would eschew aerial adulticiding and emphasize instead careful water management and the targeting of mosquito larvae (larvaciding), as some other cities do. Examples are our nation's capitol Washington, D.C., Nashville, Tennessee, and Fort Worth, Texas.

    As to efficacy, the Sacramento-Yolo Mosquito & Vector Control District (SYMVCD) has supplied no evidence that spraying adulticides is effective in slowing the transmission of WNv to humans. In fact, scientific research and mathematical modeling demonstrate that spraying is ineffective because mosquito populations quickly rebound to their prior levels. Even with this lack of efficacy the District refuses to resurrect its program of development of safe and effective biological controls.

    In spite of the scientific evidence to the contrary, public officials promote a 2008 paper about the 2005 spraying of Sacramento as evidence of efficacy, but because their work involves serious methodological and scientific problems no conclusions at all can be drawn from it. Rigorous review by independent scientists was avoided – in response to our Public Record Act requests the authors were able to produce no reviews of their paper whatsoever (item #5).

    Vector control and public health officials declare an epidemic when a certain threshold is reached, which involves infected mosquito pools, dead birds, and horses but no longer includes human cases. "Epidemic" seems to be an exaggerated word up front, particularly as many people view the term and with human infections removed from the spray trigger. They then insist that they must spray to "break the transmission cycle," an impossibility with this spray program.

    The National Centers for Disease Control (CDC) indicates that 80% of people infected with WNv will not develop any illness or symptoms, 20% will have mild flu-like symptoms, and 1 in 150 have serious symptoms. In 2011 there were 9 deaths of people in California infected with WNv (California Department of Public Health data). While any death is tragic, and while we strongly support effective preventive measures, comparing the 9 deaths in California in 2011 of people infected with WNv to the 7000 or more flu and pneumonia-related annual deaths reveals the extent of the official exaggeration. The spraying supposedly justified by an "epidemic" is then a badly out-of-proportion public health response to a relatively small threat. We always need to spend our public funds where they have the greatest positive effect, but this seems particularly true in these difficult economic times. 

Cities, counties nationwide begin mass aerial sprayings of toxic 'anti-West Nile Virus' pesticides.
     

Mosquito Aerial Spray Programs Endanger Human Health, Don’t Work.